Screw fastener



FIG. 1 is a top perspective view of a screw fastener of our new design.

FIG. 2 is a bottom perspective view of the screw fastener of FIG. 1.

FIG. 3 is a front view of the screw fastener of FIG. 1.

FIG. 4 is a left side view of the screw fastener of FIG. 1.

FIG. 5 is a right side view of the screw fastener of FIG. 1.

FIG. 6 is a top plan view of the screw fastener of FIG. 1; and,

FIG. 7 is an enlarged bottom plan view of the screw fastener of FIG. 1. 

CLAIM The ornamental design for a screw fastener, as shown and described. 